Dreammaster: The Erotic Invader (1996)

On a quest to unravel the mysteries of recurring nightmares, four college grad students experiment on each other, monitoring and attempting to manipulate their dreams. Grant, the most troubled of the quartet, is disturbed by the sensual Devora, an erotic fantasy figure who torments and teases him in the most vivid of dreams. Determined to help him, Grant's friends enter the twilight world of his sleeping mind, only to discover that Devora's curse of eternal pleasure is irresistible...